Fuso Canter versus Isuzu

[Amesz00]

arrrg! spent half an hour yesterday typing up a reply, then as i was about to post it, the power went out!

Yer, Andrew, surely that'd be because of the smaller wheels and brakes too. Not sure of the shortening?

well the NPS is 2150 over rear wheels. FSS is around 2300, im fairly sure.

Was actually talking to a good friend about this only last Sunday. He teaches auto electrics to the apprentices and in particular engine management and he was saying the power chip specialists are now starting to play around with VGT. Should have heard what he was saying about auto transmission re-programming.

yeah doesnt surprise me at all. while we all are aware of the drawbacks of these electronic motors, they do have their definite advantages, like how easy it is to pull lots of power (with the right program...).

When Andrew Says Compound, I'd say that is in series? yes...no....wait??

Hey chocko. yeah mate, compound is two turbos in series, one big, one small. not to be confused with sequentials (which some toyota cars, 1JZ, 2JZ, run), which is 2 turbos in series, but the same size, and utilizing (if im correct) a valve and bypass arrangement. so up till a certain rpm it runs on one turbo, after that the valve opens, the second comes online, and you have sequentials.
compounding is much mechanically simpler, and supports much bigger boost (over say 40-50psi is hard to attain with a single or even sequentials). you have a big and a small, on the intake, air first goes into the large (or low pressure) turbo, gets compressed then enters the small (or high pressure) turbo, where it is compressed even more then shoved into the engine. the exhaust is opposite and runs manifold, small, big.
as a matter of interest, the new MAN TGM's have a borg-warner compound setup as factory fit-out.
sorry bout the hijack, but im 18 and i love turbos...

back on topic-

Yep. 3150 would be real good. I had a very scary time in my old Fuso SWB work truck on a wet road once. Mainly my fault. BTW I've driven an FG at 4300mmWB. Mate, that sucked. It was a dirt road only bus though. Done plenty of campers at 3900 but they start to get hung up on the centre tailshaft bearing a bit because of the ramp over angle (unless they're lifted).

man, a 4.3m canter! that thing would have a turning circle of about 25m! even 3900 is pretty dang long for a small truck...

I could be wrong on the lower COG, but perhaps this is one reason the Canter has avoided the need for the “wider rails for stability” or the “front sway bar”, i.e. by keeping the COG lower.

im with WCB here- NPS straight rails are a good thing. sooo much less stuffing around for the body-builders, and i dont think that the lower COG point is really conclusive, (i dont know what ATW or earthcruiser do) but we have to build the floor up to clear the gooseneck anyway, so the only benefit i can see is that its very easy to fit underfloor watertanks.

Andrew

 

[whatcharterboat]

im with WCB here- NPS straight rails are a good thing. sooo much less stuffing around for the body-builders, and i dont think that the lower COG point is really conclusive, (i dont know what ATW or earthcruiser do) but we have to build the floor up to clear the gooseneck anyway, so the only benefit i can see is that its very easy to fit underfloor watertanks.

Andrew, what's your opinion on the 850mm v 750mm though?

 

[KEENO]

T-Box

Is the extremely low mounting location of the Transfer Case considered to be a disadvantage on the Fuso FG? ('High Centering' concern)
The Isuzu seems to have it 'tucked in' better due to the straight frame rails & shape of the case. My eye is always draw to the hanging transfer case while viewing an FG from the side.

Just curious...

KEENO

 

[nugget]

the LWB i have now will literally outrun my mates '80 series cruiser on a twisty dirt track...;P ).
As far as my opinion on best wheelbase, i think my next rig will be about 3150mm.

I am sure a responsible young bloke you would not have actually raced down twisty dirt track!!! Just out of interest, did you flog the pants off 'em....I always enjoy hearing yarns about a Cruiser having its pants lowered and its bum smacked!!

Very interested in your nominated 3150mm wheel base. can you expand on that a bit on the reasons you see that wheel base as optimum and how you would set the suspension?

 

[DzlToy]

turbos

dont want to sidetrack this too much, but you have essentially described the same setup using two different terms.

For truck pulling and diesel drag racing many people use two turbos. Use whatever term you want but essentially a SMALL turbo is used to build boost down low and has a low psi wastegate. This small turbo is then used to light a LARGE turbo, which if run by itself would be very laggy or would only make high RPM power, leaving nothing down low. Since diesels dont have huge RPM bands this allows high boost (well over 100 psi in race applications) with no lag since boost can be made from idle up to redline (5-6k rpm dep on build)

another option is to have two equally sized turbos each feeding half of a motor, typically in a V configuration, each turbo would be responsible for one bank of four cylinders. They do not feed into each other or connect as above. If the turbos are too small or too large, you will still have the same problems as an incorrectly sized single. The advantage here is that you can run a smaller to medium sized turbo and still make huge power since each turbo only feeds half the motor. A large turbo feeding the entire motor could potentially be very laggy and a small one would run out of steam on the top end.

I am not a turbo expert by any means, but I have quite a few friends with hot rod diesel trucks making 600-900 RWHP and this is typical of what I have seen.

Cheers,

Jon

Amez, did you ever get pics and specs on the crew cab truck?

 

[whatcharterboat]

Hi Keeno,

Is the extremely low mounting location of the Transfer Case considered to be a disadvantage on the Fuso FG? ('High Centering' concern)
The Isuzu seems to have it 'tucked in' better due to the straight frame rails & shape of the case. My eye is always draw to the hanging transfer case while viewing an FG from the side.

Just curious...

No It isn't a problem normally. Definetly not on the SWB FG anyway. The MWB will hit the centre tailshaft bearing first if they're going to hit at all. They might look low but they are actually about 350mm high as standard (well the one here is a little lifted but it was the closest to standard I could measure) under the transfercase. About 14" in English. The Isuzu is 410mm at standard ride height. measured a lifted NPS here at 520mm but don't have an FG on the same big wheels at the moment to compare.

Previous model NPS with 520mm (about 21") under the transfercase. The current model should be around the same.

 

[Amesz00]

Andrew, what's your opinion on the 850mm v 750mm though?

hmm, havent thought too much about it. the wider NPS chassis would give (as you say) to a more stable body, with less stress on the subframe crossmembers. one advantage of the narrow rails is more room on the sides of the truck (assuming same width body) for bins, fuel tanks etc.

I am sure a responsible young bloke you would not have actually raced down twisty dirt track!!! Just out of interest, did you flog the pants off 'em....I always enjoy hearing yarns about a Cruiser having its pants lowered and its bum smacked!!

nah, of course not! what do you take me for??...
well, either in 2wd or 4wd, ive found that this thing will pretty much turn into any corner on the dirt, at almost any speed. gets a little light on the rear so ya gotta keep ya boot in. but them tyres just grip and drive it forwards. both my mates (not the one with the 80) have been into fast cars and the like thier entire lives, thrashing bombs around paddocks etc.
on seperate occaisions i managed to make them both pack their daks (figuretively...). one corner i attacked at about 90, the mate with the 80 said he wasnt keen for more than 75...
disclaimer- i dont drive everywhere like this, but where i deem safe i do like to wind it out and see what itll do...
BTW should be much better with the new turbo and chip, etc that is the next project with it.

Very interested in your nominated 3150mm wheel base. can you expand on that a bit on the reasons you see that wheel base as optimum and how you would set the suspension?

Well, as i mentioned, dads previous rig (before his massive terrain-eating MAN) was a canter SWB, with 255 XZLs (the one in the picture floating around here somewhere). and my truck now is a dualcab, basicly similar, but with a size bigger tyres (11.00R16 XL, so more aggressive also). i loved the maneuverability of the SWB, but it is a bit unstable at speed, also offroad they tend to buck like a front-end loader. the wheelbase is 2780 (on the FG649), which is 200mm shorter than a patrol!
the longer WB dualcab (at 3380), is much more stable on road, as i said above it is very stable to slide on the dirt, and it doesnt 'buck' offroad. not to say that the ride is any good, the stock suspension is absolutely shameful! the downside of the longer truck is its much bigger turning circle (by about 4m i think), however this does make you a good reverser/driver when offroad, having to swing it around and do 3-pointers everywhere...

dont want to sidetrack this too much, but you have essentially described the same setup using two different terms.

For truck pulling and diesel drag racing many people use two turbos. Use whatever term you want but essentially a SMALL turbo is used to build boost down low and has a low psi wastegate. This small turbo is then used to light a LARGE turbo, which if run by itself would be very laggy or would only make high RPM power, leaving nothing down low. Since diesels dont have huge RPM bands this allows high boost (well over 100 psi in race applications) with no lag since boost can be made from idle up to redline (5-6k rpm dep on build)

this is basicly correct. BTW im no turbo expert either so i also could be wrong.
the first you described is a compound setup (also known as 'staged', i think), the second is a parallel setup, not normally used on inline engines.
the sequential setup i mentioned, is similar to the compound setup, but different in that both turbos are the same size, and it uses mechanical means to switch between 1 and both turbos at a preset rpm or boost.

 

[1Engine]

Sorry for the highjack

Over the years I have seen & worked on a number of engines with turbo chargers.
Use of multiple turbos, has the benefit of response time for turbo to achieve optimum operating speed & therefore keeping pollution down to a minimum & producing maximum torque. The ideal engine is 1 turbo per cylinder.

The maximum rev rate increase that a diesel can achieve is about 2000 to 2500 revs per sec. Don't try it at home with your own engine - but remove the governor & with no load it does not take long for the engine to self destruct. This is the reason why a good serviceman, after installing a new pump / governor or injector replacement on a GM, before having someone else to start the engine, will have the air induction piping removed, a steel plate at the ready to shut the engine down by starving it of air - block off the inlet manifold with the place

When running series turbos it is best to have a balance pipe between the turbos & the inlet manifold or use a common intercooler to balance the boost pressure & preferably a balance pipe between the exhaust manifolds, before the turbos to balance exhaust pressure. As it is near impossible to have all injectors delivering the same amount of fuel & therefore a load unbalance & can cause piston / crank failures

Sequential Turbos have the advantage of operating 1 turbo at optimum speed in a lower operating rev range, benefiting in lower exhaust temps & better fuel economy Eg If your truck gear shift point is 2600 rpm up to 2700rpm-one turbo operating, above 2700 rpm the second would come on line, however once on line would stay in until the rpm bogged down to 2200rpm. To bring the 2nd on line valving should open the inlet of the compressor side before opening the inlet to the turbine side- this prevents overspeed of the turbo.

I have only worked on a few compound turbo systems, these systems have run large primary turbos running at about 20k rpm feeding smaller secondary turbos running at 75k rpm. High torque engines, not very responsive.

One other system that is around is supercharged-turbocharged engine. Benefits a nice flat torque curve & good fuel economy. The mechanical driven supercharger operates at low rpm, & once turbo boost pressure reaches approx 1/2 operating pressure then the mechanical supercharger is disengaged
& the engine runs as a turbo engine. To disengage the supercharger, a valve closes off the inlet of the supercharger causing it to run in a vacuum & therefore not using energy - same method as screw-type air compressor unloads.

Just to get you thinking - not all superchargers rotate like the roots type or the centrifugal type, some of the cathedral engines run piston type superchargers

When it comes to boost specs, as some specs are given in absolute pressure. eg With the engine turned off they read 1 atmosphere- 14.7psi- 1bar. It saves confusion when setting engines up for high altitude. European manufactures are good at giving specs in absolute.

 

[engineer]

Thanks everyone for the quick lessons, I love this forum!!
Behold the ACERT Caterpillar with compounding Exhaust powered turbines in series...

 

[DzlToy]

^^ that is gorgeous, too bad its yellow

 

[1Engine]

Hi John,
Who ended up doing the fuel tank & what is the capacity? The primary fuel filter is that standard on that model
Wadey

 

[whatcharterboat]

Who ended up doing the fuel tank & what is the capacity? The primary fuel filter is that standard on that model
Wadey

Hi Dave, we tack them together here and get a specialist welder dude in town with a watercooled Tig to finish them off and pressure test them. Just under 500 liters of fuel in both these tanks. All the water tanks are between the rails. Still waiting to fit the rear mudgaurds and recovery lockers behind them.

And yes, that's the standard filter under the batteries. I haven't even found the filter on the current model yet. They just have a handy little in line lift pump above the engine fuse box.

See ya Dave, Taking your advice and going surfing. Have a big cyclone swell on the points today. Yippee!!!!!

 

[KEENO]

Great look & functionality on the tanks John!

It looks like it's ready to take on a land mine blast with the 'V' Shaped underbelly! Similar to many of the armored vehicles currently running around the Middle East.

Totally 'Bomber' for sure....

KEENO

 

[whatcharterboat]

Hi Keeno. Thanks I'll pass it on. You'd like my screen saver then.

 

[KEENO]

Perhaps some future expansion of the ATW line could include something similar. Sweet articulation on the armored troop carrier.

KEENO